Indicator



Jan. 7, 1936. 'I y P, FQ zERKLE .2,027,217

INDICATOR Filed Jan. 28, 1932 2 Sheets-Sheetl 71; 27 ze, za 2.9 30 .41 42 40 17 ',/16 a? fg 213%" :nl v i a Y E" .4 i 35 as z ,J I I [37 3a/K ,g Y lNvErJTon v l Lwz", l

ATTORNEYS Jani 7,` 1936. P. F. zERKLE rINDICATOR Filed Jan. ze, 19:2

2A Sheets-Sheet 2 Y. l INVENTOR.4

Patented Jan. 7, v 1.936

UNITED VSTATES PATENT OFFICE g z,z1,z11

raul r. lid, ohm Application January 28,-1932, serial Na. ssaisi 1 Claims.

This invention relates to measuring devices.

and more particularly to. devices for measuringV objects provided with grooves or lands,l such as threads, worms and the like.

vhelical and like grooves or projections.

Another object is to provide an improved instrument which will indicate variations in the Obliquity of helical and like grooves or :projections- Another object is to provide an improved measuring instrument which will be simple in construction and operation.

Another object is to pro'vide an improved measuring instrument which will be strong and easily maintained in adjustment.

Another object is to provide an improved measuring instrument which will be economical to manufacture. y

Other objects will hereinafter appear.

The invention `will be better understood from the description of two 'practical embodiments thereof, showing devices adapted for the ,measuring of screw threads, illustrated in the accompanying drawings, in which: l

Figure 1 is a side elevation of an instrument having three contacts for engaging a thread.

Figure 2 is an end elevation of the device of Figure 1.

Figure 3 is a plan view of the device of Figure l.

Figures 4, 5, and 6 are sectional views taken on the lines IV--IV, VV, and VI-VI respectively of the iirst three ilgures, parts being brokencaway.

Figure 'I is a View corresponding to Figure 2 but showing a device having tour thread engaging contacts applied to a piece having a correct thread.

Figure 8 is a view similar to Figure 7 showing v hcw a thread of varying helix angle ailects the device. Figure 9 is an enlarged fragmentary elevation of one form of contact; and Y .Figures 10 to 13 arefrag'mentary sectional views taken on the lines X--X to XIII- XIII respectively of Figure 9.l

The device shown in of a frame i shown as approximately c shaped, provided with a spade handle l2, and conveniently composed of a casting or forging. In the upper edge of the frame isa slotor recess 3 in which is pivoted intermediate its ends a lever or beam l by means of a pin 5. The lower end of theframe is bifurcated at 6, the furcations being spanned by a pin'or axle 'I upon which, is mounted acontact,` shown as a roller having a hub 8. and a frustro-conical wheel like contacting portion 9.

The end 0I the beam which projects above this roller is also blfurcated at l0 and spanned by a pin or shaft Il. Upon this shaft is Journailed a sleeve I2 provided with a frustro-conical roller or wheel like contacting portion I3, the sleeve being of suilicient length to prevent any axial movement of the roller, as clearly shown in Figure 6. Upon theY sleeve is journalled a second sleeve Il provided with a frustro-conical roller; or .wheel like contacting portion i5, the

second sleeve being free to move axially'upon the 20 rst, for a purpose to be hereinafter described. While the contacts are shown as rollers, free to rotate on their respective shafts, it will be obvious that contacting shoes or any other form of contact might be used. Rollers are particu- 25 larly wll adapted where measurements at one part only of a thread are desired (as at the pitch line) because of the distribution oi wear about their peripheries and consequent long lifeof the contacts. 30

A spring I 6 is interposed between the trame and beam to move the roller members carried by each toward the other, and an adjusting screw I'I passes through an aperture in the beam, and is threaded into the frame to limit the approach 35 of these rollers. f

The frame carries indicator mechanism which shows at any instant the proximity of the -two roller shafts. this being given to any desired degree oi minuteness, most conveniently in thousandths or tenths ot thousandths of an inch.

The indicator consists or a lever Il pivoted interm'ediate its ends within the beam upon a pin 2| of the lever, this adjusting screw being locked in adjusted position by a set screw 22 also threaded into the frame. I

- The long end 23 ofv the lever has a contact en- 50 l gaging a helical land 24 .upon a vertical staff 25 l journalled in the beam, which stai! is provided Figures 1 to 6 consists l at its upper end with a hand or pointer 26, moving over the graduated dial 21. A torsion spring 28 is connected between the stai! and the beam, 55

' which urges the hendin o. countercloclrwise direction, as viewed in Figure 3, causing the end 23 of the lever to beer always 'upon the upper suriece oi' the land de. A transparent cover or crystel 2s is positioned over the hemd end dial -to erm clude dirt sind the like.

A. second hidicetor mechanism is provided to indicate the axial movement or the slidable sleeve le upon non-slideble sleeve iii. This conn sists of e lever 3d having s. short end provided with a set screw 32 or other edjnstebie content engaging slee-re it or contest i5, the lever being pivoted within the besan upon e, pin 33 and heving its longer inner end odset es indicated et to bring it the interior oi the boem; .et the extremity Se or. the long end oi the lever is formed a toothed sector engaging e pinion carried. by e Lerticel ste' F Si iournalled with the beam. The upper end of the sten" is provided with a hond or pointer ist moving over the green.u ated ero or diei d@ contained within a recess in the beam adjacent the iirst mentioned diei. fr.

torsion spring el@ is interposed between end bes-m so that one side or the sector teeth engage with the cooperating side oi the pinion teeth et all times. l

A second transparent cover or crystal li oven lies this pointer and diei and is conveniently secured in piece by s covering plete it attached to the beam by screws d3, es shown in Figure 3.

The operation ci the device is as follows- When the operator wishes to engage a threed, he groeps the frame by Ineens of the handle and slides the contacting rollers onto the threaded portion Il of the piece to be measured. Each roller, of course, engeges the @ace between two successive convolutions of the thread, the two upper rollers engaging mms several convolutions apart and the lower roller being between the upper rollers and engaging a thread preferably half a. convolution away from that engaged by the upper stationary roller.

Obviously the diameter of the piece will control the distance between rollers s and i3 and variations in the 'diameter will cause the beam to swing about its pivot, being indicated by the motion of hand 2t. The distancebetween the two upper rollers will at the seme time be indicated by the hand 3e, and any variation from the desired pitch' will be shown by motion ci this hond. Of course,- the most convenient way of using the instrument is to adjust both indicators to point to zero when the correct diameter and pitch are present, as by adjusting them about a master thread, and any deviation will be readily apparent, the amount of the deviation being in dicated so that the operator can clearly see I whether it is within allowable tolerances. 'I'he apparatus when so used may be considered as an indicating comparator, at ell times comparing a, thread to the master.

If the threads do not conform to true helices but are disposed, for instance, at a. greater obliquity duringa part of a convolution than at another, there will be a tendency on the part oi the rollers on one side of the piece to be moved axially relative that on the other side. This will cause the measuring apparatus to cant or rock from side to side, this rocking being reected by an oscillating of the indicator hands, and also by the diameter indicator, registering a. diameter considerably in excess of that to which the piece was presumably cut.

The deviations of the thread from a tmc helix epee,

can more conveniently be ascertained by the instrument shown in'Flgures l sind 8, in which two contacting. members d@ and @d ere provided on the` lower part ci the apparatus, one of these being restrained against etnici movement while the other may slide axially ii desired.

As shown in the Erst ci' the two above mentioned rieures, if .the helix of the thread is correct, es the master thread el, all four rollers will be in Contact therewith, esch contesting sides of i two edacent convoiutlons. li the thread, for insta-ence, is on one side than on the other, es illustrated by @Bin Figure 8, the device will rcel: in e countercloeliwise direction, so that the left hand upper right bend losser roliers ere muted between adjacent convolotions, while the right hand roller will beer upon the side of one convolution only and the ower left hen roller will be entirely ,clear oi the thread.

Obviously, the separeting ci the two shafts thus sensed will he quite epperent on the diameter indicator (heed it) riddle the two zipper rollers will be irse to more towerd each other, showing a iiiictuation upon the lead indicetcr (hond fi@ lt will prob-silly be moet convenient to one of the lower Qontacts cut .away throughout portion ci its circumference so that it may be edportion into proximity to the thread, in which position the apparatus will operate esenti?? as did the three roller device or' the first six figures.

The additional contact may conveniently be formed es indicated in Figures 9 to 13 having plurality of didst-ent contacting segments shown g5 as, one et, adapted to engage the threads et their pitch line, a, second 5B, being out away so that it engages the threads only adjacent their root, and a third 5l, engaging the threads only adje.a cent their crest; while the fourth section 52 is formed to clear the thi-eed entirely.

Y All four contacts may he made es segmental shoes like that shown in Figures 9 to' 13, and it is then possible to accurately gauge the shape of the thread by taking three readingsone with all of them adjusted to engege this thread its pitchdiameter; another' with all adjusted to on gage at the root; end another with all. adjusted to engage at the crest. Any conce-vity or convexity oi the thread surface, or any shallowness in the depth o' the thread, is shown by the 'measurements at the depth measured.

A spring pressed detent 53 may be provided I to engage a series of notches on the contacting shoes to hold them in adjusted position or a. lock- 55 ing bolt, or other means for securing might be used. If rollers are used, bestresults will be obtained by forming them like section til so that they contact the thread at and near its pitch line.

thread, it may, of course, be applied to other helical objects, such as worms, and to other curves than the helix, as conical or spherical spirals.

It will be obvious that the lever with its two indicatorsmay be transferred from one frame to another for use on articles of differing diameters,A or that means for adjusting -one or the other of While the invention is shown as applied to a the roller supporting shafts toward the Aother mightv be providedfor this PUI'DOse.

While I have described the illustrated embodiments in some particularity, obviously many other embodiments will readily occur to those skilled in the art to which appertains, and I. therefore g5 do not limit myself .to the precise details shown and described herein, but claim as my invention all embodiments. variations -and modifications coming within the scope of the appendedv claims.

I claim: v 1. Measuring apparatus comprising a frame, a

` contacting element carried thereby, a lever pivoted to said frame, a shaft carried by said lever, a contacting element carried by said shaft and locked against axial movement thereon. another contacting element carried by the shaft. and

free to move axially thereon, an indicator indicating the motion of the lever on the frame, and

a second indicator indicating the motion of the last mentioned element on its shaft.

2. Measuring apparatus comprising a frame,

a lever pivoted thereon, a contact iixed to said frame, a contact ilxed to said lever, a contact carried by the lever and'movable thereon, an indicator carried by the lever, connectionsbetween the indicator and the frame whereby relative movement of the lever and frame are indicated, and a second indicator carried by the lever actuated by the last mentioned contact.

3. Measuring apparatuscomprlsins three contacting elements adapted to engage the walls of an external thread or the like, two on one side of the, thread and one on the opposite side, re-

silient means moving the two first mentioned elements relatively toward each other, resilient means moving the first two elements relatively toward the third mentioned element,- measuring means for measuring the distance between 'the first two mentioned elements, vand. measuring means for measuring the distance between the third mentioned element and the two flrst mentioned elements.

4. Measuring apparatus for measuring a helical thread or the like'comprising a frame, a lever movable relative to eachother, and the pairs being movable relative to each other, measuring mechanism for indicating the distance between the pairsof elements, and measuring mechanism for indicating the distance between the elements of'one pair. ,4

6. Measuring apparatus, comprisinga frame, a contacting element carried thereby, a support movably carried by the frame, a contacting element carried by said support. one oi said contact- 3? ing elements comprising two relatively movable contacts, means urging said contacting elemcnts toward each other, measuring means indicating the distance between said contacting elements.

means urging said contacts toward each other. s

and measuring means indicating the distance between said contacts.

'L'Measuringapparatus Y a i{rame.a lever pivoted thereon, a con t xed to said frame, a contact fixed to said lever, a contact 10 carried' by the lever and movablel thereon, an indicator carried by the lever, connections between the indicator and the frame where relative movement of the lever and frame are indicated. a second indicator carried by the lever actuated by 151 the last mentioned contact. said contact: each comprising an element adapted to be adjusted about an axis and having a plurality of contacting surfaces of trapezoidal cross-section. the pairs of inclined sides of all the sections being 20 at the same angle to each other and the intersection of said pairs of inclined sides if projected beingatthesamedistancefromtheaxis.the bases of the trapezoidoi each section being disposed at different distances from said axis than 25 'i those of each of the other sections. 8. Measuring apparatus comprising a frame, a

movable support carried thereby, parallel shafts one iournalled on the frame and the other in "the support, a plurality of contacting elements 30 upon each of said shafts, the elements on one shaft being axially movable relative to each other, an indicating mechanism showing the relative position of said contacts on said shatt, and a second indicating mechanism. showing the rela- 35' tive position ofthe support and frame.

9. Measuring apparatus for measuring helical threads or the like, including a plurality of contacting elements each supported for adjustment about'its' axis, eachelement having a plurality 40 of contacting surfaces and beng'of trapezoidal cross-section, lthe pairs of inclined sides of all the sections' being disposed at the same angle to each other and the intersection of said pairs of inclined' sides if projected being at the same diss tance from the axis, the bases of the irapemid of each section being disposed at diiferent distances from said axis than those of each of the 'other sections.

10. Measuring apparatus for measuring helical 5o threads or the like, including a plurality of contacting elements each consisting of a pivoted member having bearing portions concentric with the axis of its pivot and each supported for adjustment about its axis, said bearing portions 55 -lying in two oppositely convex conical surfaces and dened by dierent .sones in -said conical surfaces.

P. 1". ZERKLE. 

